Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Java Java Data Structures Efficiency! Changing Course

I added the video, there are no errors. Still, the Check work button tells me that I should add the video.

What am I missing?

package com.example.model;

import java.util.List;

public class Course {
  private String mName;
  private List<Video> mVideos; 

  public Course(String name, List<Video> videos) {
    mName = name;
    mVideos = videos;

  public String getName() {
    return mName;

  public List<Video> getVideos() {
    return mVideos;

package com.example.model;

public class Video {
  private String mTitle;

  public Video(String title) {
    mTitle = title;

  public String getTitle() {
    return mTitle;

  public void setTitle(String title) {
    mTitle = title;

import com.example.model.Course;
import com.example.model.Video;

import java.util.Map;
import java.util.LinkedList;

public class QuickFix {

  public void addForgottenVideo(Course course) {
    // TODO(1):  Create a new video called "The Beginning Bits"
    Video video = new Video("The Beginning Bits");
    // TODO(2):  Add the newly created video to the course videos as the second video.
    LinkedList<Video> videos = new LinkedList<>();
    videos.add(1, video);

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {


  public Map<String, Video> videosByTitle(Course course) {
    return null;


1 Answer

Seth Kroger
Seth Kroger
56,403 Points

It's looking for the video to be added to the course's list, not a list that's only local to the method.

Shaun Smith
Shaun Smith
12,145 Points

Sorry, I thought videos was the course's list. I don't understand, please explain a little more.

Thank you,